A gas turbine is formed of a compressor, a combustor, and a turbine, and high-temperature and high-pressure compressed air is generated by compressing air taken from an air inlet with a compressor. In the compressor, fuel is supplied to burn the compressed air, and a high-temperature and high-pressure combustion gas drives the turbine to drive a generator connected to the turbine. In this case, the turbine is formed by alternately disposing a plurality of turbine vanes and turbine blades inside a vehicle interior, an output shaft connected to the generator is rotatively driven by driving the turbine blades with the combustion gas. Then, the combustion gas having driven the turbine becomes a flue gas, and discharged to the atmosphere through an exhaust duct.
In the above-described gas turbine, the exhaust duct is provided with a heat insulation material on an inner surface side to cope with high-temperature of the flue gas. In other words, the exhaust duct in the related arts has a configuration in which a plurality of stud bolts is fixed to an inner surface of a cylindrical-shaped duct at a predetermined interval, and further the heat insulation material is uniformly disposed, and a top end portion of the stud bolt and a heat insulation panel are fixed with a nut.
Examples of the exhaust duct having the above-described configuration in the related arts are disclosed in Patent Literatures 1 to 3 listed below.